For your purposes, I think I would suggest private lessons, for the following reasons.

Most classes are about money or politics. When an instructor works for a range, and that range furnishes the weapons, ammo and lane, as well as the instructor's wages, the curriculum is what the owner of the range says it is. He's interested in income, not education. His curriculum will be a mix of what he believes and what sells.

The NRA is no different in this respect. Their aims are primarily political, with a strong second place going to money. Teaching under the NRA's programs, there are several subjects included in the basic courses that I'm not sure you would benefit from. "Why We Own Guns" is an example of one such subject.

My suggestion, therefore, would be an independent instructor, who is willing to tailor his curriculum to what you need. Not cheap, and you will probably have to demonstrate some knowledge, (I don't believe someone knows weapons just because they say they do) but it may go further towards accomplishing what you're after.

The problems will remain the same, however. It's a capitalist country. In this case, the main capital is the range, the next the weapons, and finally the insurance and the ammo. Those are the people who will dictate what you can buy as far as instruction. So you may have to compromise some of your desires to find a legitimate instructor, with insurance and range access. On the other hand, you may find that a standard class fits your needs, and you may end up gaining more knowledge than you thought you would by taking one.